Relay



C. A. BODDIE Deq. 15, 1925- RELAY Filed May 4,1920

I INVENTO'R ficzrence/f. Bacid 1e ATTORNEY Patented Dec. 15, 1925.

UNITED" STATES PATENT OFFICE.-

CLARENCE .A. IBOTJDIE, OF PITTSBURGH,

HOUSE ELECTRIC & MANUFACTURING- COMPANY,

VANIA.

Application filed May 4,

T0.aZZ whom it may concern:

Be it known that I, CLARENCE A. BODDIE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Relays, of which the following is a specification. My' invention relatesto relays and particularly to polarized relays.

' One object of my invention isto provide a relay structure that shall be simple and relatively inexpensive lIICOIlStI'UCtlOIl and that shall be controlled either in accordance with the power supplied by a circuit or in accordance with the direction of current flowing through said circuit.

In many regulator systems, it is desirable to provide a relay structure whichis operat-, ed directly in accordance with the watts supplied by a circuit. Thus, for example, in an electric furnace system, it is very desirable to operate a relay in accordance withthe power supplied to an electrode-in order toeifect control of such electrode in accordance with the delivered watts. It is also often desirable to provide a polarized relay structure thatshall be operated in accordance with the direction of current flow through a circuit. Other applications of the relay described herein will be apparent from the following specification.

Preferably, my relay structure comprises;

two series coils are symmetrically located,

with respect to the core armature, and being wound in opposite directions, it is apparent the series connected coils can'efiect no move.- ment of the core member-without the aid of the polarizing winding. \Vhen the three coils are simultaneously energized, the magnetic field produced by thecentral winding co-operates' .with the magnetic fields pro- PENNSYLVANIA, ASSIGNOR TO WESTING- A CORPORATION OF PENNSYL- RELAY.

1920. Serial No. 378,731.

duced by the two'series-connected coils for moving the core armature in a direction determined in accordance with the directions of current flow through the coils. The direction of movement of the core armature may be changed-by. reversing the current flow either through the central coil or through the two series-connected coils.

In operating. the relay structure in accordance with the watts delivered by asupply circuit, thecentral winding is preferably energized accordance with the potential obtaining on such circuit and the seriesconnected windings' are energized. ill accordance with the value ofthe current flow ing through the circuit. Thus, the core with the watts supplied by the circuit.

In the accompanying drawing, Fig. 1 is a dragrammatlcvlew of a relay constructed. in accordance with my invention and, connected toa supply circuit, and Fig. 2 is adlagra'mmatic View of'the relay structure indicating the magnetic fields produced by the various coils.

Referring to the drawing, prises a core armature 2 and coils 3, 4 and The coil .4 is! centrally located with respect to. the core armature 2 and the coils 3 and 5 are located uponopposite sides of the coil 4. The coils 3 and 5, which are a relay 1 com-' armature is operated directly'in accordance connected in series-circuit relation, are

equal number of turns.

The eore'armature 2 is pivotally connected to a contact arm 6 Whichselectively eon nects a conductor 7 to conductors 8 and 9 wound in opposite directions and comprise in accordance with the operation of the relay structure. I -A spring member lO-is provided for so counter-balancing the weight of the core memberQ asto maintain the con- 'tactarmfi in a neutral position, as, shown, when the'coils 3, 4 a'hd 'evarenormally energizech 'The coil 1 is connectedv across a supply circuit comprising conductors 11 and 12 in-order tobe energized in accordance with the volt'age obtaining in the supply circuit and the coils 3 and 5 arei-connected to acurrenttransformer 13 in order to be energizedin accordance with the ourrent flow through the supply circuit. The

coils 3, 4 and 5 are stationaryand have no movement relative-to each other.

The--coil-4: is assumedto produce a magnetic -field;which is represented by the ar- I 'rows14in Fig. 2 of the drawing. The coil no'moven1ent of the core armature 2 rela 3 is assumed to producea magnetic field which'is represented'by the arrows 15 and the coil 5 is assumed to produce a magnetic field which, is represented by the arrows 16.

If the coil a is energizedalone and the two coils 3 and5 are de-energized, it'is ap arent that the magnetic field produced wil effect tive to the coil 4. However, the coil 4 pro- .duces a magnetic field which polarizes the core armature 2 in accordance with the direction of current flow throughthe coil.

If the two coils 3 and 5 are energized and j the coil 4 is de-energized, it is apparent no movement of the core armature 2 relative to the two coils will be effected. The two coils and 5 are symmetrically disposed relative to'the core armature 2, and, inasmuch as the two coils are wound in opposite directions, it is apparent the magnetic fields produced are neutralized. In case the three coils are simultaneously energized, the core armature 2 1s moved in-accordance with the produce magnetic fields which 'jointly tendto move the core armature 2 in amupward direction, If the'current flow through'either' the coil-4 or through the-coils 3 and 5 be reversed, it is apparent that the directionof I movement of the core'a'rr'nature' 2 would be changed. I v -'In the system shown in Fig. 1, the relay structure 1 is operated directly in accord- I ance with the watts supplied by the circuit supplied by the circuit the contact arm 6 is comprising conductors 11 and '12. When normal power is supplied by the circuit'the core armature 2 and the contact arm" 6 are retained in a neutral osition with the conductor 7' disconnecte from the conductors 8 and 9. Such positionis maintained by the magnetidaction of thecoils assisting the spring 10 in supporting the core armature 2. If more than a normal number; of watts is raised to connect the conductor 7 with conductor 8, The spring 10 has not sufficient strength of itself to su ort the core armature 2. Consequently, it less than a normal number of watts is supplied by the conductors 11 and 12,- the core armature 2 and the 'contact arm 6 re allowed to drop and effect connection be ween conductors 7 and 9.

In order to more clearly show that the core member 2 is operated directly in accordance with the watts passing through the circuit comprising conductors l1 and 12, the magnetic efiects of the coils 3, 4- and 5 will 4 and 5.

be considered in detail. If the core membl 2 were controlled solely by the current co -3, it is apparent it would be moved'in a cordance with a constant and the square l the value of the current flowing through 'tl coil 3. Assuming P to be the magnet force of the coil 3 acting onthe core 'mer ber 2, K to be a'constant for such coil a! I to be the current'fiowing through the c( thenwe have the equation P -K 1 l the same manner, thecoil 5 exerts a ma netic force 1".,'=K 'I Inasmuch as thetv coils'3 and.5 are wound with an equal nui ber of turns and are connected in serie circuit relation, it-is apparent the force I is equal and opposite to the force, P

: i The middle coil 4 is centrallylo'cated a1 produces no magnetic .force which acts. rectly to effect movement. of the core mel ber 2. However, the coil 4 produces a ma netic'field .H which reacts upon the'fiel produced by the coils 3 and 5 to effect mov ment of the core member 2. The magnet field H producedby the core'4 varies 1n :1

,- cordance with the voltage E of the supp circuit and, accordingly, it may be'stat that the magnetic field H equals a consta IQXE. The magnetic fields produced l the coils 3, and 5 vary in accordance with t current I. passing through such coils. A cordingly, it may be stated that the magnet field produced by thecoil treacts upon-t magnetic fields produced by the coils 3a; 51tO'p1OdllCe a magnetic effect or force whi is equal to K,EI. Consequently, the C0] bined *magneticefiects P of the three co is equal to K I .K I +K,EI.' Inasmu as the quantities K I and K 1 are eqr and opposite, it ,is apparent the force ull of the coils upon the core member is equal to ILEI. Thus, it is apparent t core member 2'is moved in accordance wi the watts flowing through the supply of cuit comprising conductors 11 and 12. It also will be obvious that the relay illt trated in the drawing may be equally 1 used'for power-factor correction, maintai ing the same relation between the coils For example, an ap lication this invention toa three-phase delta-co nected winding may be assumed.

It is well known that the vector line re resenting the currentat the apex ofja t1 angle will be at right angle to the vect line representing the voltage across the ha of the triangle at power factr Hence, if the voltage-coil 4 is connect across the baseof the triangle, and t] current coils 3 and 5 connected to the-ap .of the triangle, the contact arm 6 will 0 cupy a neutral position at 100% pow factor, If the power factor should va from 100%, the variation would produce force which,.acting against the potential the relay, would either .pull orpush t1 contact arm 6 in such manner to effect the operation of mechanism designed for .power factor correction.

In other words, the current I in a trans former connected at the apex of the triangle,

times the voltage E represented by the base of the triangle, times the cosine of the angle therebetween at 100% power factor equals a zero. Hence, the magnetic pull on the core 2 of the relay at this time will be zero.

The power factor at which the relay will be operative may be adjusted by cross-connecting series transformers in circuit with each of the windings, and connecting the potential Winding to an auto transformer.

Modifications in the structure and in the arrangement and location of the parts may be made within the spirit and scope of my invention, and such modifications are intended to be covered by the appended claims.

I claim as my invention 1 1. In a system comprising a source of alternating current, a movable core member, a

polarizing winding for magnetizing said core member and for normally holding the said core member and for normally-holding said core member centrally thereof, lneans for energizing the other coils. for varying the position-of the maximum flux density.

with respect to the position of said coils for varying the position of said core member.-

3. A watt relay comprising a movable core member, a voltage coil for magnetizing said core and for normally holding the core cen-,

trally thereof, and a pair of current coils symmetrically disposed with'respect, to said voltage coil and connected in opposition to each other, said coilscooperating to actuate said core in direction and degree'in accordance with the energization ofsaid coils.

4. In a system comprising a source of al- 'ternating current, a relay comprising -a movable core member, afixed coil wound about said core for normally holding the core member centrally thereof, and two lixed coils oppositely wound about said core on opposite sides of said first-named coil, said three coils cooperating. to actuate said core member in accordance with the phase angle between the sources of energization of said coils.

. 5. Arelay comprising three coils placed along substantially the same axis, a core armature within saidcoils, two circuits for said relay, one of said circuits comprising the central one of said three coils,'the other circuit comprising the other two of said coils differentially related to each other so that the normal position ofsaid core caused by the ener ization of either of said two circuits will e substantially the same, and the variation of said core from said neutral position will be responsive to the energization of said circuits.

6. In combination, a circuit, a p1unger-. type relay comprisinga movable core memher and three windings associated therewith,

two of said windings being' differentiallyconnected, and means for energizing saidwindings in accordance with the voltageand current in said circuit to actuate said core member in accordance with the direc,- tion of power flow therethrough.

-7. In combination, a circuit, a plungertype relay co'mprisinga movablecore meme her and three windings associated therewith, two of said windings being differentially connected and disposed at the ends of said core member, and means for energizing said windings in accordance with. the voltage and current'in said circuit to actuate sa1d core -member in accordance with the amount and direction of power flow therethrough.

,8. In combination, a power. circuit, a plunger type relay comprising three coils placed along substantially the same axis, a core member movable within said coils, two circuits for said relay, one of' said relay cir- .cuits comprising the central one of said three coils, the other of said relay circuits comprising the other two of said coilsdifferentially related, and means for connecting said relay circuits to saidpower circuit to be energized in accordance -with the circuit to actuate said core member-in accordance with the direction of power flow therethrough. i 3

In "testimony whereof, I have hereunto igggcribed iny, name this 29th day of April,

CLARENCE A. BODDIE.

voltage and with the current of said power 

